Sheet metal stair structure



Dec. 8, 1931. T. L. COOK SHEET METAL sum STRUCTURE Filed Feb. 21, 1931 INVENTOR Theodore L. Cook ATTO RN EYS Patented Dec. 8, 1931 UNITED STATES 'rATENroFFIo THEODORE L. COOK, OE AKRON, onmnssrenoe To THE OEHAHEHTAL IRON wOEK COMPANY, OF AKRON, OHIO, A CORPOEATIO E oHIo sHEET METAL sTAIEsTaUOTnR Application filed february 21, 931. Serial No. 517,474.

This invention relates to sheet metal stair structures.

Heretofore many different types of sheet metal stair structures have been provided 1n operations are required in addition to those required for forming the units with treads,

risers and nosings. Moreover considerably more material is utilized to form the interlocking flanges than was required in the old bolted types of stair structures. Another objection has been that the curvature of a downwardly curved flange on the nosing results in the plastic filling usually used on the treads forming a feather edge over the curved portion of said flange which cracks or breaks away and leaves an unsightly joint between the nosing and the plastic material. Also the flow of the plastic material under the nosing is interfered with by -p rovision of adownwardly turned, interlocking flange on the nosing. In accordance with one heretofore suggested form of stair structure, interlocking tangs are struck down from the top nosing flange, but this construction utilizes considerably more metal due to the. width of the interlocking flange on the tread. The apertures in the nosing of this type of stair structure must have the plastic material forced therein to the surface and the material in these apertures appear as spots of contrasting color.

The present invention has for its object the provision of a stair structure of the above type in which a minimum of metal is employed, in fact but little more than required for the old bolted constructions, in which only one bending operation is required to form a single narrow'flange upon the tread portion of each unit, in which there are no feather edges of plastic material formed at thejoints between said material and the nosing, in which the plastic material flows with out interference under the nosing, and in which thepresence'of unsightly apertures in the nosing is avoided.

The foregoing and other purposes of the invention are attained in=the sheet m'etal stair structure illustrated in-the accompanyingdrawings and described below. It is to be understood that theinvention is not limited-to the specific form thereof shown and described. f

Of the accompanyingdrawings,

Figurel is a longitudinal'section through a stair structureembodying. the invention; F1g'ure2 is an enIarged' -detail' section showing the interlocking connection between the tread and r ser un1ts;

- Fi-gureB is a section on line 3-3 of Figure 2;and' Figure-dis a perspective-view of a portion ofa tread and riser unit showing the arrangement of interlocking clips thereon.

1 Referring to 'thedrawingathe numeral 10 designates oneof the stringerswhich may be suitable metal strips, preferably channels onto which angle-brackets 11, 11 for supporting. thestair structure may be secured as by spot welding orthe like indicated at 12, 12. The stair structure includes tread and riser units 13, 13, each'of which is formed with a rearwar'dly'and angularly'bent flange 14 on the front edge of the tread and with a for- 30 wardly'extended channel shaped portion 15 at the top of the riser portion to provide a nosing. Each unit has secured thereto inside of the channel nosing a-series of spaced clips 16, 16 secured thereto as by welding and providing downwardly turned channels with which the flange 14 of vanotherunit may interlock [with f the forward margin of the. tread of the other unit engaged in the lower side of the nosing channel. Theclips 16 preferably are located as low as possible in the nosing channel so that flange'14 may be of minimum widthand so that the clips are spaced from the upper flange .of the nosing 15 whereby the plastic material 17 filled on the treads between the nosing and riser may flow withoutinterference under the top flange of the nosing. .The

iinterlocked units may be secured upon the mo angle-brackets 11 in any suitable way as by bolts 18, 18.

It will be apparent that the joint at 19 between the nosing 15 and the material 17 is defined by an abrupt edge of the sheet metal so that there will be no feather edge of the plastic material 17 formed '.=at this. point to crack or break away and become unsightly or form an obstacle over which one may trip and fall.

It will be apparentfrom the foregoingthat a simple, eflective and more economical interlocking sheet metal stairway structure has been provided by the invention, Modifica tions of this structure may, of course, be resorted-ate without-departing from the spirit of the invention or thescope of theappended claims.

cWhatis claimed is 1. An ,interloekjirgsheet metal stair structure comprising tread and riseri'mits each formedrof: sheet; metal withanos'i-ng at the top of the-riser, and spaced clipssecured inside the nosing at a point spaced downwardly from the upper part ofthenosing, said upper 'part'of' thenosinghaving-an abrupt end for defininga jointbetweenthe nosing and plastic materialfilled on the tread, and said tread having aflange on, its forward; edge extending rearWardly-at an angle whereby one nn t may be interlocked-With another :by engagement of the forward portion of the tread on one unit with thernosing on an adjacent unit Withsaid tread flange engaged, under said clis. '1

An, interlockingsheet; metal stair structure comprising tread and riser units each formed of sheet metal with a nosing at, the topof the riser, and spaced clipssecured inside the nosing at a point spaced? downward- Ly from the upper partlof the nosing, said treadxhaving, a flange onjits forward edge extending rearwardly at an angle whereby one unit may be interlocked with another by engagement of the forward portion of the treadon one unit with the nosing onan adjacent unit with said tread flange engaged under said clips.

3. An interlockin sheet metalstai'r strucb ture comprising tread and riser units each formed of sheet metal with a nosing at the top of'the riser, and spaced clips secured inside the nosing at a point spaced downwardly-from the upper part of the-nosing,said upper part of the nosing'having an abrupt end for defining a joint betweenthe nosing and plastic material filled on the tread, and said tread havinga flange on its forward edge whereby oneunit may be interlocked with another by engagement of the forward portion of the tread on one unit with the nosing on an adjacent unit with said tread flange engaged under said clips.

i 4. An interlocking sheet: metal stairistructure comprising tread andriser units each formed of sheet metal with a nosing at the top of the riser, and spaced clips secured inside the nosing at a point spaced downwardly from the upper part of the nosing, said tread having a flange on its forward edge whereby one unit may be interlocked with another by engagement of the forward portion of the tread on one unit with the nosing on an ad- 'acent unit with said tread flan e en 'a ed D D be tending rearwardly at an angle whereby one unit may be interlocked with another by engagement of the forward portionof the tread on oneun t with the nosing on an ad acent unit with said tread flange engaged under said clips.

6; An interlocking ture con'iprising tread and riser units each formed of sheet metal with a nosing at the top oftthe riser, and spaced clips secured inside the nosing, said nosing being lmperforate,

andsaid tread having a flange on itsforward edge extending rearwardly at an angle whereby one unit may be interlocked with another by engagement off the forward portionof thetread on one unit with the nosing 1 onan adjacent. unit with said tread flange engaged under said clips.

'7. An interlocking sheet metal stair structure comprising tread and riser units each formed of sheet metal with a topof the. riser, and spacedclips securediuside the nosing, said upper part of the nosing being imperforate and havingan abrupt end for defininga joint between the nosing and plastic material filled on the tread, and said tread having a flange on its forward edge whereby one unit may be interlocked with another by engagement of the forward portion of the tread on one unit with the nosing on an adjacent unit with said tread flange engaged 7 under said clips.

8.. Aninterlocking sheet metal stair structure comprisin tread and riser units each formed of sheet metal with a nosing at the top of the riser, and spaced clips secured inside the nosing, said nosingbeing imperforate, and said tread havin-gaflange on its forward edge whereby one unit may be interlocked with another by engagement of the forward portion of the tread on one unit with the nosing'on an adjacent unit with said tread flange engaged under said clips. v

9. An interlocking sheet metal stairstructureincluding tread and riser units each formed with a nosing at the top of the riser,

sheet metal stair strucnosing at the i'- and spaced clips secured within the nosing at a point below the top of the nosing, said units having a flange on the forward portion of the tread to engage in the nosing of an adjacent unit under said clips to interlock the units.

10. An interlocking sheet metal stairway construction including tread and riser units, each unit being formed with an imperforate nosing at the top of the riser and having spaced clips Within the nosing, each of said units having a flange on the forward portion of the tread to engage With the nosing and clips of an adjacent unit to interlock the units. THEODORE L. COOK. 

